Casing for electrical apparatus



Nov. 27, 1928. 1,693,265

A. o. AUSTIN CASING FQR ELECTRICAL APPARATUS Original Filed Juhe 25, 1924' 2 sheets-snag 1 4 3 41 V 7 4'0 30 v I 39 31 42 as I Nov. 27, 1928. 1,693,265

A. o. AUSTIN CASING FOR ELECTRICAL APPARATUS Original Filed June 25, 1924 2 Sheets-Shet 2 entire column of liquid within the leg. The cup 43;, however, has sullicicnt capacity to retain the liquid so that after thcpressure has been relieved, the safety U-tubc will automatically restore itself because of the difference in the-size of the legs of the U seal, the seal offers less resistance to ingress than it does to egress of air.

In many installations the-windings do not conform to the contour of the transformer housings. \Vhere this is the case, advantage may be taken of the extra space. within the housing for a compression tank such as that shown at 47. This tank is open at its lower end and provides a pocket-48 in its upper portion fori'air orgass a r-pipe 49 is provided having'a. valveSO through which the pressure in the tank 47 wilLbe controlled. T his'compression chamber; 48 will provideadditional facilityior expansion and contraction of the oil in the-housing '26. At the same time it will efiect an-economy of oil-since it occupies space which it would otherwise be necessary to fill'with the insulating oil. The form ofcompr ession tank shown :zt47 has: especial'adva-ntages in connection with casings i for circuit; breakers, high potential switches and other. ap 'aratus which may pro- -duceTan:-.are,within 1'. c2 housing; =The.com- -pre'ssion tank-,has its op'en'end in -municat-ion:with.thebody of: the; liquid in the 'h'ousingso thateany pressure. shock. is immediatel communicated :top'ro I preci'able time la direct cpmto the-air or gas inthe the compression tank'without-any ap- -'sueh as islp'resentwiththe o'rdi'nar -;form 0 conservator tank or other reliefevice connected with, theL housing through arestricted pas- A: j-furtheri advantage; isthat since the openendzotthecompression tank is near the Ebottom of the. housing, there'is practically-no danger at, any gasproduc-ed-inthe housing by an arc or.".othe,r cause' tentering the compres- .sion tank; and; forming; amexplosive mixture ;m the compression space A ny gas generated in the houslng will rise tot-he top of thehousing: where it maypermitted. to escape through any suitablereliet. devicesuch as the ',-trap 44, --.-The compression. tank 47 .will thus compensate. for variations of pressure between limits andwill also relieve sudden pressure shocks and give the blow-off ,device time to operate. to-permit -theescape of gas pro duced simultaneously with theshock'and thus restore normal pressure with1n.t -hehousing.

If the gas producedis of an explosive nature or such that itwould form arr-explosive mixture with the-gasin the compression chamber,.

it is; prevented from .endangeringthe housing because thegenerated gas is allowed to escape without entering the-compression chamber. Y I 3 ilar to that of Fig. ever, the transformer hers, and a hquidseal for saidweiit :of anda gas space in' the uppeh. i oa s: S ee leve efhe qi 'd... a

for supplying liquidfto indj a liq n aid.

with the interior said other leg thereof.

. electrical-apparatus, ofmeanslformir'rg acornp a j and a U-tube seal In Fig.- 3 there is. shown a construction simthereof to control the escape of gas through provided with cooling coils 51 and a plurality t compression tanks 47 are provided below these coils. These tanks are connected at their tops by pipe 52. The compression tank 53 in this instance is raised above the top level of the oil in the housing and is connected with the interior of the housing by means of a conduit 54. The tank 53 may be a horizontally extending cylinder partially filled with oil, as indicatedby tlic gauge glass 55. This will maintain a liquid head on the housing 26 which may be augmented by gas or air pressure in the top of the tank 531 A U-tube seal or trap 44 similar to that in Fig. 1'seals the tank 53 to atmosphere and provides a safe ty blow-out to take care ofprcssure too great to be taken care of by. the resiliency of the gas in the tank 52..' In the Utubes inbotliin stances porous diaphragms 56 and-57 are pro} vided of suitable material, such as ,cliarnois skin or other-substance that; will permit passage of air but prevent overflow of the liquid; Iclaim: i- '1 .f' 1. A housing for electrical apparatus hay;- ing two conductor e ite riding through the top thereotyi sup'po 'rts' jorisaid bushings providing cha jb'erfsi's lirroiitiding the interior portions thereofifnieans jorc'onnee-ting said chambers to' perinitjthepa's'sage of air from one toj'the othn'g a Inunicating with the top of "one of 2. In combination withhousiiig foi jele'ctricel rp i o bnshi g:' i n s through the top ofsai hqusingja pedestal carried by said housing for shppbrting sai bushing and iorming a ehainberab'outth'e m innerportioniof bushing, expansion tank having liquid 'n the lower pfoi ti'o rtherer t-mistreatbeing e w-the ap ifia l 'i ii' i means ndu l mmilm atienjwiflii tion of said chamber and 'openn g' below 1 1 o .3. T ief-fiem ina electrical lappar'at'usj o ,a compression chamber expansion and contractlon o l gul t'l n sa d housmg, d a l -s a lr e isla i: q ap sion chamber, sa 1d seal hayi'nggone'leg thereofconnected with said compres nchai'nber and of greatercross-sectional area :the

i 4. The combination pression; chamber communicated with the interior of said housing-t .pe rm1t expansion the liquid of said seal. 13o

5. The combination with a housing for electrical apparatus having insulating liquid therein, of means disposed within said housing below the surface of said liquid for providing a gas pocket to facilitate expansion and contraction of said liquid said pocket being open at its bottom and closed at its top.

6. The combination with a housing for electrical apparatus arranged to contain an insulating liquid, of a compression chamber communicating with the interior of said housing, and a U-tube seal for said compression chamber, said U-tube seal having one leg of larger diai'neter than the other and connected with said COIDPIGSSlOIl chamber, the other leg of said U-tube being open to the atmosphere and having an enlarged cup for preventing overflow of liquid from said U-tube.

7. The combination with housing for electrical apparatus, of a compression chamber connnunicating with said hou ing, and a liquid seal for said compression chamber, said liquid seal comprising a U-tube having one leg connected with said compression chamber and the other leg communicating with the atmosphere, there being a restriction for limiting the rate. of escape of gas through said U-tube.

8. The combination with a housing for electrical apparatus, of a pedestal extending upwardly from said housing, an insulator bushing extending through said pedestal and closing the top thereof, a compression tank having a chamber separate from said housing, a conduit connecting said chamber with the upper part of the interior of said pedestal, and a U-tube seal connected with said chamher.

9. The combination with a housing for electrical apparatus, of a compression chamber connected With said housing, a U-tube seal for said compression chamber, said seal having one leg connected with said chamber and the other leg open to atmosphere, and a baflle pervious to gas but impervious to liquid for preventing entrance of the liquid from said seal into said chamber.

10. The combination with a housing for electrical apparatus having insulating liquid therein, of a compression tank closed at its top and open at its bottom and having a pocket of gas entrapped therein, said compression tank having its lower open end positioned near the bottom of said housing.

11. The combination with a housing for electrical apparatus having insulating fluid therein, of a compression tank disposed entirely Within said housing below the surface level of the liquid in said housing, said tank being closed at its top for retaining a pocket of gas, the lower portion of said tank having free communication with the liquid in said housing at a point below the major portion of the electrical apparatus in said housing.

12. The combination with a housing for electrical apparatus of a trap connecting said housing with atmosphere, said trap comprisa liquid seal having legs of different cross sectional areas through which gas passes to and from said housing when the pressure within said housing differs from the pressure outside of said housing by predetermined amounts, the leg adjacent said housing having a greater sectional area than the leg communicating with the atmosphere to permit escape of gas from said housing through said legs at a less pressure difference than that at which gas enters said housing through said legs.

In testimony whereof I have signed my name to this specification on this 11th day of November, A. D. 1925.

ARTHUR O. AUSTIN. 

